Indexable stump cutter tooth

REFERENCE TO EARLIER RELATED PATENT APPLICATION

This patent application is based upon U.S. Provisional Patent Application Ser. No. 60/856,173 filed on Nov. 2, 2006 by Ritchey et al. for an INDEXABLE STUMP CUTTER, and applicants claim priority on said provisional patent application (i.e., U.S. Provisional Patent Application Ser. No. 60/856,173 filed on Nov. 2, 2006 by Ritchey et al. for an INDEXABLE STUMP CUTTER), which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention pertains to a cutter tooth that has a hard insert at the axial forward end wherein the cutter tooth is useful to impinge and/or disintegrate a piece of material such as, for example, wood or earth strata. More specifically, the invention pertains to such a cutter tooth (such as, for example, an indexable stump cutter tooth), that when used in a stump cutter machine allows the stump cutter machine to experience an increase in operational efficiency (i.e., a reduction in operational downtime), as compared to a stump cutter machine that used earlier stump cutter teeth.

Heretofore, there have been machines used to impinge and/or disintegrate materials such as, for example, wood and/or earth strata. These machines have included (without limitation) machines used to cut or disintegrate wood or brush such as, for example, land-clearing machines, tub grinders, stump cutters and force feed grinders.

In the case of stump cutter machines (i.e., stump cutters), they have a plurality of teeth or stump cutter teeth mounted in the vicinity of the periphery (including without limitation at or near the circumference of) a driven wheel. The stump cutter is positioned near the stump, and then the wheel is driven (or rotated) and then moved in a radial sweeping motion whereby the moving stump cutter teeth impinge the stump. After having made a number of cuts or passes into the stump, the result is that the stump has been disintegrated below the surface of the ground. Exemplary patent documents that disclose a stump cutter include U.S. Pat. No. 6,024,143 to Ritchey for a CUTTING TOOTH ASSEMBLY, U.S. Pat. No. 5,497,815 to Bowling for a CUTTING TOOTH, U.S. Pat. No. 5,743,314 to Puch for a STUMP CUTTING TOOL ASSEMBLY, and U.S. Pat. No. 4,998,574 to Beach for a CUTTING BIT AND BLOCK MOUNT.

In a stump cutting operation, it is desirable for the stump cutter machine to maintain an optimum operational efficiency (i.e., a reduction in operational downtime). Operational efficiency of the stump cutter machine can be impacted by a number of factors including without limitation the ability of the stump cutter tooth assembly used by the machine to resist breakage and/or wear (and especially premature breakage and/or wear) of any component of the stump cutter tooth or the pocket (i.e., the holder that carries and retains the stump cutter tooth). Operational efficiency of the stump cutter machine is also impacted by being able to easily place back into service a stump cutter assembly used on the machine that has experienced (without limitation) a worn or damaged stump cutter tooth or a worn or damaged pocket.

Stump cutter teeth, as well as the supporting structure (i.e., the pocket), experience a great deal of stress during the stump cutting operation. During the stump cutting process, stump cutter teeth can experience catastrophic breakage, as well as become worn past a point of usefulness. Breakage or wear can occur in the steel body of the stump cutter tooth or in the axial forward hard insert affixed to the steel tooth body. When a stump cutter tooth breaks or wears past a point of usefulness, the stump cutter machine must be stopped, and the tooth must be replaced with another stump cutter tooth. The time and expense connected with the replacement of stump cutter teeth reduces the overall operational efficiency of the stump cutter machine (or apparatus). It would be advantageous to provide an improved stump cutter tooth that experiences a reduction in events (e.g., the breakage or wear) that require replacement thereof.

During the stump cutting process, the pockets (including the bolts or fasteners retaining the cutter tooth to the pocket) can also experience breakage and/or wear to such an extent that they must be replaced. Breakage of the fasteners (or bolts) can cause damage to the wheel to which the stump cutter teeth are mounted. Further, the bore in the pocket, which carries the stump cutter tooth, may elongate in cross-section due to wear over time so as to be detrimental to the overall cutting process. The time and expense connected with the replacement of the pocket or components thereof also reduces the overall operational efficiency of the stump cutter apparatus. It would be advantageous to provide an improved stump cutter tooth assembly (including the pocket and associated components) that experiences a reduction in events (e.g., the breakage or wear) that require replacement of the other components of the stump cutter tooth assembly including without limitation the pocket and associated fasteners.

It is inevitable that a stump cutter tooth, as well as other components of the stump cutter tooth assembly, will eventually break or wear past a point of usefulness to require replacement with another stump cutter tooth or pocket. This being the case, it would be highly desirable to provide an improved stump cutter tooth, as well as an assembly (including a pocket) that uses the improved stump cutter tooth, that enhances the operational efficiencies connected with replacement of stump cutter teeth or other components of the stump cutter assembly.

SUMMARY OF THE INVENTION

In one form thereof, the invention is a stump cutter tooth held by a pocket member, which has a first edge and a second edge, wherein the pocket member is operatively attached to a driven wheel, which has opposite first and second side surfaces. The stump cutter tooth comprises an elongate tooth body that has an axial forward end, a first hard region that is at the axial forward end of the tooth body and defines at least one distinct cutting edge that has an orientation to engage the stump during operation of the driven wheel. The stump cutter tooth has a second hard region that is at the axial forward end of the tooth body. The second hard region is distinct said one direction. The first abutment surface is in operative engagement with the first shoulder of the pocket member to prevent rotation of the stump cutter tooth with respect to the pocket member. The pocket member has a second position disposed on and operatively attached to the second side of the cutting wheel. The stump cutter tooth has a second position with respect to the pocket member when the pocket member is in the second position thereof with respect to the cutting wheel. The second abutment surface of the stump cutter tooth is in contact with the second shoulder of the pocket member whereby the leading edge of the stump cutter tooth is reversed and thereby shields the second edge of the pocket member and the second shoulder of the pocket member from wear.

In another form thereof, the invention is a stump cutting tool assembly for a stump cutting apparatus that has a rotatable cutting wheel with an outer periphery. The stump cutting tool assembly comprises a tool holder operatively removably attached to the cutting wheel. The tool holder comprises a wheel portion that extends circumferentially adjacent the outer periphery cutting wheel and a tool portion disposed at least partially radially outwardly from the wheel portion wherein the tool portion has an aperture disposed therein. The stump cutting tool assembly further includes a cutting tooth operatively removably attached to the tool holder. The cutting tooth has an unobstructed front face and a shank attached to the front face and extending rearwardly from the front face. The shank is disposed at least partially in the aperture of the tool holder. The front face of the cutting tooth has a first hardened portion and a separate second hardened portion whereby chipping of one of the first or second hardened portions does not immediately cause chip damage to the other of the first or second hardened portions of the front face due to the non-continuous nature of using separate first and second hardened portions instead of using one continuous unobstructed front face.

BRIEF DESCRIPTION OF THE DRAWINGS

The following is a brief description of the drawing figures that form a part of this patent application:

<figref idrefs="DRAWINGS">FIG. 1</figref> is an isometric view of a stump cutter assembly in engagement with a stump wherein the pocket members and stump cutter teeth as disclosed in the present patent application are used with this stump cutter assembly;

<figref idrefs="DRAWINGS">FIG. 2</figref> is an isometric view of the forward portion of the stump cutter assembly of <figref idrefs="DRAWINGS">FIG. 1</figref> illustrating a plurality of stump cutter tooth assemblies mounted (or operatively attached) to the driven cutting wheel;

<figref idrefs="DRAWINGS">FIG. 3</figref> is an isometric view of a driven cutting wheel with the components of several stump cutter tooth assemblies exploded away from the side surfaces (e.g., first side surface and second side surface) of the cutting wheel;

<figref idrefs="DRAWINGS">FIG. 4</figref> is a view of one edge of a straight pocket member such as illustrated in <figref idrefs="DRAWINGS">FIG. 3</figref>;

<figref idrefs="DRAWINGS">FIG. 5</figref> is an isometric view of the straight pocket member as illustrated in <figref idrefs="DRAWINGS">FIG. 4</figref>;

<figref idrefs="DRAWINGS">FIG. 5A</figref> is an isometric view of a pair of spaced-apart, oppositely disposed straight pocket members showing their position relative to one another when mounted (or operatively attached) opposite each other on a cutting wheel;

<figref idrefs="DRAWINGS">FIG. 6</figref> is a side view of a specific embodiment of a cross-over pocket member, which attaches to a side surface of the driven cutting wheel, that retains a stump cutter tooth;

<figref idrefs="DRAWINGS">FIG. 7</figref> is a view of one edge of the cross-over pocket member of <figref idrefs="DRAWINGS">FIG. 6</figref>;

<figref idrefs="DRAWINGS">FIG. 8</figref> is a view of the other edge of the cross-over pocket member of <figref idrefs="DRAWINGS">FIG. 6</figref>;

<figref idrefs="DRAWINGS">FIG. 9</figref> is a cross-sectional view of the cross-over pocket member taken along section line <b>9</b>-<b>9</b> of <figref idrefs="DRAWINGS">FIG. 8</figref>;

<figref idrefs="DRAWINGS">FIG. 10</figref> is a cross-sectional view of the cross-over pocket member taken along section line <b>10</b>-<b>10</b> of <figref idrefs="DRAWINGS">FIG. 9</figref>;

<figref idrefs="DRAWINGS">FIG. 11</figref> is an isometric view of a cross-over pocket member;

<figref idrefs="DRAWINGS">FIG. 12</figref> is an isometric view of an offset pocket member;

<figref idrefs="DRAWINGS">FIG. 13</figref> is a side view of the offset pocket member of <figref idrefs="DRAWINGS">FIG. 12</figref>;

<figref idrefs="DRAWINGS">FIG. 14</figref> is a view of one edge of the offset pocket member of <figref idrefs="DRAWINGS">FIG. 13</figref>;

<figref idrefs="DRAWINGS">FIG. 15</figref> is a view from the other edge of the offset pocket member of <figref idrefs="DRAWINGS">FIG. 13</figref>;

<figref idrefs="DRAWINGS">FIG. 16</figref> is a cross-sectional view of the offset pocket member taken along section line <b>16</b>-<b>16</b> of <figref idrefs="DRAWINGS">FIG. 13</figref>;

<figref idrefs="DRAWINGS">FIG. 17</figref> is a cross-sectional view of the offset pocket member taken along section line <b>17</b>-<b>17</b> of <figref idrefs="DRAWINGS">FIG. 14</figref>;

<figref idrefs="DRAWINGS">FIG. 18</figref> is an isometric view that shows the components of a stump cutter assembly exploded apart from one another in relation to a driven cutting wheel wherein these components comprise a pair of oppositely disposed offset pocket members, a pair of cap screws, a stump cutter tooth (the embodiment of <figref idrefs="DRAWINGS">FIG. 21</figref>) for each one of the offset pocket members and a nut used to secure each stump cutter tooth to its respective one of the offset pocket members;

<figref idrefs="DRAWINGS">FIG. 19</figref> is an isometric view of one specific embodiment of the stump cutter tooth of the invention wherein two separate hard inserts are affixed to the axial forward end of the stump cutter tooth;

<figref idrefs="DRAWINGS">FIG. 20</figref> is an isometric view of the axial forward end of the stump cutter tooth of <figref idrefs="DRAWINGS">FIG. 19</figref> with the hard inserts removed;

<figref idrefs="DRAWINGS">FIG. 21</figref> is an isometric view of another specific embodiment of a stump cutter tooth (which is the preferred stump cutter tooth) wherein two separate hard inserts are affixed to the axial forward end of the stump cutter tooth and the axial rear end of the shank is threaded;

<figref idrefs="DRAWINGS">FIG. 22</figref> is an isometric view of the stump cutter tooth of <figref idrefs="DRAWINGS">FIG. 21</figref> retained by the offset pocket such as that shown in <figref idrefs="DRAWINGS">FIG. 12</figref>;

<figref idrefs="DRAWINGS">FIG. 23</figref> is a view from one edge of two straight pocket members (with a stump cutter tooth mounted in each pocket) mounted (or operatively attached) to the cutting wheel in the vicinity of the periphery thereof;

<figref idrefs="DRAWINGS">FIG. 24</figref> is a view from one edge of a cross-over pocket member and an offset pocket member (with a stump cutter tooth mounted in each pocket) mounted (or operatively attached) to the cutting wheel in the vicinity of the periphery thereof;

<figref idrefs="DRAWINGS">FIG. 25</figref> is a view from one edge of two offset pockets (with a stump cutter tooth mounted in each pocket) mounted (or operatively attached) to the cutting wheel in the vicinity of the periphery thereof;

<figref idrefs="DRAWINGS">FIG. 26</figref> is a side view showing a stump cutter tooth assembly (i.e., stump cutter tooth and pocket) mounted (or operatively attached) to the cutting wheel in the vicinity of the periphery thereof wherein there is shown radial arcs that illustrate the clearance between the cutting edge of the stump cutter tooth and the top surface (or radial outer surface) of the pocket;

<figref idrefs="DRAWINGS">FIG. 27</figref> is a side view of another specific embodiment of a stump cutter tooth of the invention wherein the stump cutter tooth has three separate hard inserts affixed to the axial forward end thereof;

<figref idrefs="DRAWINGS">FIG. 28</figref> is a front view of the stump cutter tooth of <figref idrefs="DRAWINGS">FIG. 27</figref>;

<figref idrefs="DRAWINGS">FIG. 29</figref> is an isometric view of another specific embodiment of a stump cutter tooth of the invention wherein the single monolithic hard insert presents three separate cutting edges;

<figref idrefs="DRAWINGS">FIG. 30</figref> is a front view of the stump cutter tooth of <figref idrefs="DRAWINGS">FIG. 29</figref>;

<figref idrefs="DRAWINGS">FIG. 31</figref> is a side view of another specific embodiment of a stump cutter tooth of the invention wherein a single monolithic cutting insert presents four separate arcuate cutting edges; and

<figref idrefs="DRAWINGS">FIG. 32</figref> is a front view of the stump cutter tooth of <figref idrefs="DRAWINGS">FIG. 31</figref>.

DETAILED DESCRIPTION

Referring to the drawings, in <figref idrefs="DRAWINGS">FIG. 1</figref> there is illustrated a stump cutter assembly (generally designated as <b>20</b>) that is in engagement with a stump (designated as “STUMP”). Stump cutter assembly <b>20</b> uses the stump cutter tooth assemblies (e.g., stump cutter teeth and pockets) shown and described in this patent application. This particular stump cutter assembly (or stump cutter machine) is a Vermeer SC352 stump cutter made and sold by Vermeer Mfg. Co., 1210 Vermeer Road East, Pella, Iowa 50219. However, there is no intention to limit or restrict the scope of the invention to any specific type or kind of stump cutter assembly.

Still referring to <figref idrefs="DRAWINGS">FIG. 1</figref>, stump cutter assembly <b>20</b> has an arm (or frame) <b>22</b> with a distal end and to which is operatively rotatably attached a driven cutting wheel <b>26</b> about a first axis A-A. Driven cutting wheel <b>26</b> has a circumferential (or peripheral) edge <b>28</b> and a radial outer portion that has its radial outer termination at the circumferential edge. Driven cutting wheel <b>26</b> has opposite side surfaces that comprise a first side surface <b>29</b>A and a second side surface <b>29</b>B. A plurality of stump cutter tooth assemblies is affixed to the cutting wheel <b>26</b> in the vicinity of the peripheral edge <b>28</b> of the driven wheel. <figref idrefs="DRAWINGS">FIG. 2</figref> shows the forward portion of the stump cutter assembly of <figref idrefs="DRAWINGS">FIG. 1</figref> wherein a plurality of stump cutter tooth assemblies are mounted to the driven wheel.

A stump cutter tooth assembly comprises a stump cutter tooth and a pocket member that affixes (or is operatively attached) to one or the other of side surfaces (i.e., a first side surface <b>29</b>A or a second side surface <b>29</b>B) of the cutting wheel near the periphery thereof. As will be described in more detail hereinafter, there are three different styles of pocket members (i.e., a straight pocket, a cross-over pocket and an offset pocket). Each one of these styles or kinds of pocket members includes an extension (or radial outer portion that is reduced in both width and thickness as compared to the radial inner portion of the pocket member) that contains a bore. The stump cutter tooth is attached to the pocket member by positioning the shank of the stump cutter tooth in the bore and, at least for one specific embodiment of the stump cutter tooth, tightening a nut onto the threaded portion of the shank to secure the stump cutter tooth to the pocket member.

Referring to <figref idrefs="DRAWINGS">FIG. 3</figref>, there is illustrated in isometric fashion a driven cutting wheel <b>26</b> with selected ones of the components of a plurality of stump cutter assemblies exploded away. In this regard, <figref idrefs="DRAWINGS">FIG. 3</figref> shows an offset pocket member <b>360</b> (which retains a stump cutter tooth) oppositely disposed from a straight pocket member <b>230</b> (each of which retains a stump cutter tooth <b>300</b>) exploded away from each one of the side surfaces (first side surface <b>29</b>A and second side surface <b>29</b>B) of the cutting wheel. <figref idrefs="DRAWINGS">FIG. 3</figref> also shows a pair of oppositely disposed cross-over pocket members <b>260</b> (each of which retains a stump cutter tooth <b>300</b>) exploded away from each one of the side surfaces (<b>29</b>A, <b>29</b>B) of the cutting wheel. <figref idrefs="DRAWINGS">FIG. 3</figref> further shows a pair of oppositely disposed offset pocket members <b>360</b> (each of which retains a stump cutter tooth <b>300</b>) exploded away from each one of the side surfaces (<b>29</b>A, <b>29</b>B) of the cutting wheel. Stump cutter tooth <b>300</b> is shown in <figref idrefs="DRAWINGS">FIG. 21</figref> and is described in more detail hereinafter.

As is known by those of ordinary skill in the pertinent art, the stump cutter is positioned near the stump, and then the wheel is driven (or rotated) (see directional arrow “R” in <figref idrefs="DRAWINGS">FIG. 1</figref>) and then moved in a radial sweeping motion (see directional arrow “S” in <figref idrefs="DRAWINGS">FIG. 1</figref>) whereby the stump cutter teeth impinge the stump. After having made a number of cuts or passes into the stump, the result is that the stump has been disintegrated below the surface of the ground. As mentioned hereinabove, United States patent documents that disclose a stump cutter include U.S. Pat. No. 6,024,143 to Ritchey for a CUTTING TOOTH ASSEMBLY, U.S. Pat. No. 5,497,815 to Bowling for a CUTTING TOOTH, U.S. Pat. No. 5,743,314 to Puch for a STUMP CUTTING TOOL ASSEMBLY, and U.S. Pat. No. 4,998,574 to Beach for a CUTTING BIT AND BLOCK MOUNT. Each one of the above patents is hereby incorporated by reference herein.

Referring to <figref idrefs="DRAWINGS">FIGS. 4</figref>, <b>5</b> and <b>5</b>A, one of the styles of the pocket members used to hold a stump cutter tooth is a straight pocket generally designated as <b>230</b> and which is illustrated in <figref idrefs="DRAWINGS">FIGS. 4</figref>, <b>5</b> and <b>5</b>A. Straight pocket <b>230</b> includes a body <b>232</b> that has a radial inner end <b>234</b> and a radial outer end <b>236</b>. Pocket body <b>232</b> also has an outer side surface <b>238</b> and an opposite inner side surface <b>240</b>. When the pocket <b>230</b> is securely affixed to the driven cutting wheel, the inner side surface <b>240</b> is pressed against a selected one of the side surfaces of the cutting wheel <b>26</b>.

Pocket body <b>232</b> has an enlarged (or base) portion <b>242</b> adjacent to the radial inner end <b>234</b> thereof. Pocket body <b>232</b> further includes a reduced portion <b>252</b> that extends from and is integral with the base portion <b>242</b>. As can be seen from <figref idrefs="DRAWINGS">FIG. 4</figref>, base <b>242</b> has an enlarged thickness and width as compared to the rest of the cutter body (i.e., the reduced portion). The enlarged portion <b>242</b> contains a pair of bores <b>244</b> and <b>246</b> therein. As illustrated in <figref idrefs="DRAWINGS">FIGS. 4</figref>, <b>5</b> and <b>5</b>A, bore <b>244</b> is a smooth bore that includes an enlarged counterbore portion (that has an enlarged diameter) section <b>248</b> and a reduced diameter section <b>250</b>. A shoulder <b>251</b> provides a transition between the enlarged counterbore portion <b>248</b> and the reduced diameter portion <b>250</b> of the bore. Bore <b>246</b> is a threaded bore wherein the threaded portion is of a generally constant diameter. Bore <b>246</b> has a frusto-conical portion <b>247</b> at the one end thereof adjacent to the inner side surface <b>240</b>. The assembly or fastening of the straight pocket to the cutting wheel will be described hereinafter.

The straight pocket member <b>232</b> has opposite edges <b>258</b>A and <b>258</b>B. Reduced portion <b>252</b> contains a bore <b>256</b> that passes between the opposite edges <b>258</b>A and <b>258</b>B thereof. Although it will be described in more detail hereinafter, a stump cutter tooth is positioned within the bore <b>256</b> and is then retained therein.

A shoulder <b>254</b>A and <b>254</b>B is on each one of the opposite edge surfaces (<b>258</b>A and <b>258</b>B, respectively) at a location near where the pocket body transitions between the base portion and the reduced portion. Shoulder <b>254</b>A corresponds to first edge <b>258</b>A and shoulder <b>254</b>B corresponds to second edge <b>258</b>B. Again, although it will be described in more detail hereinafter, when attached to the straight pocket member, a stump cutter tooth engages a selected one of the shoulders to help keep the stump cutter tooth from rotating during the stump cutting operation. It can be said that the shoulder <b>254</b> functions as an abutment or a stop with respect to the stump cutter tooth.

It should be appreciated that each one of the shoulders (<b>254</b>A and <b>254</b>B) is spaced apart from the bore <b>256</b> a distance that is sufficient to permit the operator to use a wrench (or other tool) to easily tighten or loosen the nut that secures the stump cutter tooth to the pocket. Easy access to the nut increases the serviceability and reduces downtime connected with the operation of the stump cutter.

<figref idrefs="DRAWINGS">FIG. 5A</figref> is an isometric view of a pair of the straight pockets <b>230</b> spaced apart from one another in a fashion that represents the relative orientation between these straight pockets <b>230</b> when attached to the driven cutting wheel <b>26</b>. In this regard, <figref idrefs="DRAWINGS">FIG. 3</figref> shows (although in an exploded condition) where a pair of oppositely disposed straight pocket members <b>230</b> is operatively attached to the cutting wheel.

In regard to the attachment of the straight pockets <b>230</b> to the first side surface <b>29</b>A and the second side surface <b>29</b>B of the cutting wheel <b>26</b>, these straight pocket members <b>230</b> are attached to the cutting wheel <b>26</b> in a fashion like that for the offset pockets as shown in <figref idrefs="DRAWINGS">FIG. 18</figref>. Keeping in mind the description of the attachment of the offset pocket members set forth hereinafter, when the straight pocket members <b>230</b> are positioned relative to the cutting wheel <b>26</b> as shown in <figref idrefs="DRAWINGS">FIG. 3</figref> and relative to each other as shown in <figref idrefs="DRAWINGS">FIG. 5A</figref>, one cap screw <b>600</b> passes through the smooth bore <b>244</b> and through a corresponding aperture in the cutting wheel so as to engage the threaded bore <b>246</b> in the opposite pocket member <b>230</b>. The shoulder of the cap screw <b>600</b> that provides a transition between the head and the threaded shank abuts against the corresponding shoulder <b>251</b> and the threaded shank threadedly engages the threaded bore <b>246</b>. The same operation is done for cap screw <b>610</b>, except that it passes through the smooth bore of the opposite straight pocket member and through the corresponding aperture in the cutting wheel and into threaded engagement with the threaded bore in the opposite pocket member <b>230</b>. Each one of the cap screws (<b>600</b>, <b>610</b>) is securely tightened so as to firmly and securely attach the straight pocket member to the driven cutting wheel.

Although it will be discussed in more detail hereinafter, the cap screws used to secure any one of the kinds of pockets to the wheel are typically tightened to a greater torque than for the nuts used to attach the stump cutter teeth to the pockets. Since the stump cutter teeth are tightened to a lesser torque than the pocket bolts, it is easier to detach the stump cutter teeth from their respective pockets than to detach the pockets from the wheel. Thus, the ability to replace the stump cutter tooth by detaching only the tooth as opposed to the entire pocket, comprises an advantage that reduces downtime.

It should be appreciated that the straight pocket <b>230</b> is bi-directional in the sense that it can be positioned and reattached to the opposite side surface of the wheel. This becomes especially important in the event the forward face or one of the edges of the pocket <b>230</b> becomes damaged during use. If this occurs, the pocket <b>230</b> can be removed from the wheel, rotated 180 degrees about the axis M-M (see <figref idrefs="DRAWINGS">FIG. 5</figref>) and moved to the other side of the wheel. By doing this, the previously forward face (which was damaged) becomes the rearward face and the previously rearward face becomes the forward face. In order for this to be the case, the reduced portion <b>252</b> (or most of the reduced portion) of the pocket is symmetrical about the central axis M-M as shown in <figref idrefs="DRAWINGS">FIG. 5</figref>. The corresponding opposite straight pocket also has to be switched to its opposite side of the wheel. This bi-directional feature allows for the easy and quick reuse of a damaged pocket.

The bi-directional feature can be shown through the orientation of the pockets <b>230</b> in <figref idrefs="DRAWINGS">FIG. 5A</figref>. One can consider that the straight pocket <b>230</b> on the left side as viewed in <figref idrefs="DRAWINGS">FIG. 5A</figref> is attached to the cutting wheel with a stump cutter tooth retained thereby and rotated in such a direction that the left face is the forward face or edge <b>258</b>B. In such an orientation, the edge <b>258</b>B experiences the greatest extent of wear, as compared to the rearward face or edge <b>258</b>A, due to impingement of cutting debris thereon. What this means is that the rearward face or edge <b>258</b>A would typically not experience much wear due to the impingement from the uncut stump and/or the cutting debris as does the forward edge <b>258</b>B.

Further, it should be appreciated that when the stump cutter tooth is mounted in the bore <b>256</b> of the pocket <b>230</b>, the Cutting insert that is not in direct engagement with the stump helps protect the edge <b>258</b>A and the shoulder <b>254</b>A from wear due to impingement. The orientation of the stump cutter tooth <b>300</b> in the offset pocket member <b>360</b> as illustrated in <figref idrefs="DRAWINGS">FIG. 22</figref> is representative of the pocket <b>230</b> carrying a stump cutter tooth.

On occasion the edge <b>258</b>B (or shoulder <b>254</b>B) may suffer damage such that the pocket no longer functions in a useful (or optimum) fashion. In this embodiment, rather than replace the straight pocket <b>230</b> with a new straight pocket, the operator can remove the partially damaged (or worn) straight pocket and reposition it on the other side of the wheel so as to have an orientation like that of the right hand (as viewed in <figref idrefs="DRAWINGS">FIG. 5A</figref>) straight pocket. After being repositioned, it can be seen that the previous forward face (edge <b>258</b>B which was damaged or worn) becomes the rearward face and the previous rearward face (edge <b>258</b>A) becomes the forward face that experiences most of the impingement of the cutting debris. The corresponding opposite straight pocket also has to be switched to its opposite side of the wheel so that the bores correspond to one another (i.e., a bore with the counter bore in one pocket must correspond to a threaded bore of the other pocket). Although it will be mentioned hereinafter, it should be appreciated that the other pockets (i.e., the cross-over pocket and the offset pocket) disclosed hereinafter also have the bi-directional capability wherein the bi-directional capability of the pockets enhances the serviceability of the stump cutter assembly and reduces downtime for the stump cutter assembly.

Another kind of the pocket members is a cross-over pocket generally designated as <b>260</b> and is shown in <figref idrefs="DRAWINGS">FIGS. 6 through 12</figref>. Cross-over pocket <b>260</b> includes a body <b>262</b> that has a radial inner end <b>264</b> and a radial outer end <b>266</b>. Pocket body <b>262</b> also has an outer side surface <b>268</b> and an inner side surface <b>270</b>. When the pocket <b>260</b> is securely affixed to the driven wheel, the inner side surface <b>270</b> is adjacent to and pressed against either the first side surface <b>29</b>A or the second side surface <b>29</b>B of the cutting wheel.

Pocket body <b>262</b> has an enlarged (or base) portion <b>272</b> adjacent to the radial inner end <b>264</b> thereof. Pocket <b>262</b> further includes an angled (reduced dimension) portion <b>282</b> that extends from and is integral with the base portion <b>272</b>. As can be seen in <figref idrefs="DRAWINGS">FIGS. 6 through 8</figref>, base <b>272</b> has an enlarged thickness and width as compared to the rest of the cutter body (i.e., the reduced portion <b>282</b>). The base <b>272</b> contains a pair of bores <b>274</b> and <b>276</b> therein. Bore <b>274</b> includes a counterbore (enlarged diameter) section <b>278</b> and a reduced diameter section <b>280</b>. There is a shoulder <b>283</b> at the joinder of the counterbore portion <b>278</b> and the reduced diameter bore portion <b>280</b>. Bore <b>276</b> is a threaded bore that is of a constant diameter except for a frusto-conical mouth <b>281</b> adjacent to the inner side surface thereof.

The cross-over pocket member <b>260</b> has opposite edges <b>288</b>A and <b>288</b>B. Angled portion <b>282</b> contains a bore <b>286</b>, which has opposite frusto-conical mouths, that passes between the front surface and the rear surface (or between the opposite edges <b>288</b>A and <b>288</b>B, i.e., a first edge and a second edge) of the pocket <b>260</b>. Although it will be described hereinafter, the stump cutter tooth is positioned within the bore <b>286</b> and is retained therein.

There are opposite shoulders (or abutments) <b>290</b>A and <b>290</b>B at a location near where the pocket body transitions between the base portion and the reduced portion. Shoulders <b>290</b>A and <b>290</b>B correspond to opposite edges <b>288</b>A and <b>288</b>B, respectively. Again, although it will be described in more detail hereinafter, the stump cutter tooth engages a selected one of the shoulders (<b>290</b>A and <b>290</b>B) to help keep the stump cutter tooth from rotating during the stump cutting operation.

In regard to the attachment of the cross-over pockets <b>260</b> to the first side surface <b>29</b>A and the second side surface <b>29</b>B of the cutting wheel <b>26</b>, these cross-over pocket members <b>260</b> are attached to the cutting wheel <b>26</b> in a fashion like that for the offset pockets as shown in <figref idrefs="DRAWINGS">FIG. 18</figref> or for the straight pockets <b>230</b> as described above. When the cross-over pocket members are positioned relative to the cutting wheel <b>26</b> as shown in <figref idrefs="DRAWINGS">FIG. 3</figref> and relative to each other as shown in <figref idrefs="DRAWINGS">FIG. 5A</figref>, one cap screw <b>600</b> passes through the smooth bore and through a corresponding aperture in the cutting wheel so as to engage the threaded bore in the opposite cross-over pocket member. The shoulder of the cap screw <b>600</b> that provides a transition between the head and the threaded shank abuts against the corresponding shoulder and the threaded shank threadedly engages the threaded bore. The same operation is done for cap screw <b>610</b>, except that it passes through the smooth bore of the opposite straight pocket member and through the corresponding aperture in the cutting wheel and into threaded engagement with the threaded bore in the opposite cross-over pocket member. Each one of the cap screws (<b>600</b>, <b>610</b>) is securely tightened so as to firmly and securely attach the cross-over pocket member or its mating (or corresponding) pocket member to the driven cutting wheel.

It should be appreciated that a cross-over pocket <b>260</b> is typically used in conjunction with an offset pocket member <b>360</b> or a straight pocket member <b>230</b>. However, in an instance where the wheel is very thick, two cross-over pockets <b>260</b> may be used in conjunction with one another.

As mentioned above, the cross-over pocket <b>260</b> is also bi-directional as shown in <figref idrefs="DRAWINGS">FIGS. 7 and 8</figref>. In this regard, when the cross-over pocket <b>260</b> is attached to second side <b>29</b>B of the cutting wheel <b>26</b> as shown in <figref idrefs="DRAWINGS">FIG. 8</figref>, the left hand (edge <b>288</b>A) surface (as viewed in <figref idrefs="DRAWINGS">FIG. 6</figref>) of the cross-over pocket <b>260</b> experiences the greater extent of abrasive wear due to impingement by the stump and cutting debris as compared to the right hand edge <b>288</b>B. Further, it should be appreciated that when the stump cutter tooth is mounted in the bore <b>286</b> of the pocket <b>260</b>, the cutting insert that is not in direct engagement with the stump helps protect the edge <b>288</b>A and the shoulder <b>290</b>A from wear due to impingement. The orientation of the stump cutter tooth <b>300</b> in the offset pocket member <b>360</b> as illustrated in <figref idrefs="DRAWINGS">FIG. 22</figref> is representative of the pocket <b>260</b> carrying a stump cutter tooth. Should edge <b>288</b>A (or shoulder <b>290</b>A) become damaged, the pocket <b>260</b> could be removed from the wheel and reattached on the first side surface <b>29</b>A of the wheel as shown in <figref idrefs="DRAWINGS">FIG. 7</figref>. After reattachment, the edge <b>288</b>B (right hand edge as viewed in <figref idrefs="DRAWINGS">FIG. 6</figref>) would become the leading surface and experience the most impingement by the stump and cutting debris.

The third type of pocket is an offset pocket member generally designated as <b>360</b> and is shown in <figref idrefs="DRAWINGS">FIGS. 12 through 18</figref>. Offset pocket <b>360</b> includes a body <b>362</b> that has a radial inner end <b>364</b> and a radial outer end <b>366</b>. Pocket body <b>362</b> also has an outer side surface <b>368</b> and an inner side surface <b>370</b>. When the pocket <b>360</b> is securely affixed to the driven cutting wheel <b>26</b>, the inner side surface <b>370</b> is adjacent to and pressed against a selected one of the first or second side surfaces (<b>29</b>A, <b>29</b>B) of the wheel <b>26</b>.

Pocket body <b>362</b> has an enlarged (or base) portion <b>372</b> adjacent to the radial inner end <b>364</b> thereof. Pocket <b>362</b> further includes an angled (reduced dimension) portion <b>382</b> that extends from and is integral with the base portion <b>372</b>. Base <b>372</b> has an enlarged thickness and width as compared to the rest of the cutter body (i.e., the reduced portion <b>382</b>). The base <b>372</b> contains a pair of bores <b>374</b> and <b>376</b> therein. Bore <b>374</b> includes a counterbore (enlarged diameter) section <b>378</b> and a reduced diameter section <b>380</b>. There is a shoulder <b>383</b> at the joinder of the counterbore portion <b>378</b> and the reduced diameter bore portion <b>380</b>. Bore <b>376</b> is a threaded bore that is of a constant diameter except for a frusto-conical mouth <b>381</b> adjacent to the inner side surface <b>370</b> thereof.

Offset pocket <b>360</b> has opposite edges <b>392</b>A and <b>392</b>B. Angled portion <b>382</b> contains a bore <b>386</b>, which has opposite frusto-conical mouths, that passes between the opposite edges <b>392</b>A and <b>392</b>B. Although it will be described hereinafter, the stump cutter tooth is positioned within the bore <b>386</b> and is retained therein. There are opposite shoulders (or abutments) <b>390</b>A and <b>390</b>B at a location near where the pocket body transitions between the base portion and the reduced portion. Again, although it will be described in more detail hereinafter, the stump cutter tooth engages a selected one of the shoulders <b>390</b>A and <b>390</b>B to help keep the stump cutter tooth from rotating during the stump cutting operation.

As mentioned above, the offset pocket <b>360</b> is also bi-directional as shown in <figref idrefs="DRAWINGS">FIGS. 13 through 15</figref>. In this regard, when the offset pocket <b>360</b> is attached to the second side surface <b>29</b>B of the cutting wheel <b>26</b>, the left hand (edge <b>392</b>A as viewed in <figref idrefs="DRAWINGS">FIG. 13</figref>) of the cross-over pocket <b>360</b> experiences the greater extent of abrasive wear due to the impingement of the stump and cutting debris as compared to the right hand edge <b>392</b>B. Further, it should be appreciated that when the stump cutter tooth is mounted in the bore <b>386</b> of the pocket <b>360</b>, the cutting insert that is not in direct engagement with the stump helps protect the edge <b>392</b>A and the shoulder <b>390</b>A from wear due to impingement. The orientation of the stump cutter tooth <b>300</b> in the offset pocket member <b>360</b> is illustrated by <figref idrefs="DRAWINGS">FIG. 22</figref>. Should edge <b>392</b>A (or abutment <b>390</b>A) become damaged, the pocket <b>360</b> could be removed from the wheel and reattached on the other side of the wheel as shown in <figref idrefs="DRAWINGS">FIG. 14</figref>. After reattachment, the edge <b>392</b>B (the right hand edge as viewed in <figref idrefs="DRAWINGS">FIG. 13</figref>) would become the leading surface and experience the most impingement by the stump and cutting debris.

Referring especially to <figref idrefs="DRAWINGS">FIG. 18</figref>, there is shown a pair of opposed offset pockets <b>360</b> with the stump cutter tooth <b>300</b> (of <figref idrefs="DRAWINGS">FIG. 21</figref>), which are adapted to be retained to each one of the offset pockets, shown exploded out of the bores <b>386</b>. This pair of offset pockets is oriented apart from one another in a fashion that represents the relative orientation between the offset pockets <b>360</b> when operatively assembled to the driven cutting wheel <b>26</b> wherein a pair of cap screws (<b>600</b>, <b>610</b>) passes through corresponding apertures (or holes) in the cutting wheel and engages the corresponding bores in the opposite offset pockets.

The description for cap screw <b>600</b> passing through smooth bore <b>374</b> and the aperture in the cutting wheel for threaded engagement with the threaded bore <b>376</b> of the opposing offset pocket member <b>360</b> applies to cap screw <b>610</b>. As shown in <figref idrefs="DRAWINGS">FIG. 18</figref>, one cap screw <b>600</b> enters and passes through smooth bore <b>374</b>. Cap screw <b>600</b> continues to pass through the aperture in the cutting wheel and into threaded bore <b>376</b>. Cap screw <b>600</b> is tightened until the shoulder <b>604</b> of the cap screw <b>600</b> that provides a transition between the head <b>606</b> and the threaded shank <b>608</b> abuts against the corresponding shoulder <b>383</b> and the threaded shank <b>608</b> threadedly engages the threaded bore <b>376</b>. Each one of the cap screws (<b>600</b>, <b>610</b>) is securely tightened so as to firmly and securely attach each one of the offset pockets to the driven wheel.

As mentioned and described above, each one of the pockets (i.e., the straight pocket, the cross-over pocket and the offset pocket) is bi-directional. What this means is that for each type of pocket member, one side surface of the pocket member faces (and the other side faces away from the) one side surface (<b>29</b>A or <b>29</b>B) of the cutting wheel when the pocket member is in a first position relative to the cutting wheel. The other side of the pocket member faces (and the one side faces away from the) the other side surface of the cutting wheel when the pocket member is in a second position relative to the cutting wheel. The bi-directionality feature provides a number of advantages as described below.

One advantage is that the cost of manufacture of the pockets is lower than for pockets that are not bi-directional. In this regard, the steel body used for both the cross-over pockets and the offset pockets is the same. The difference between the cross-over pocket and the offset pocket resides in the machining of the bores. One does not have to have two different steel bodies to make these pockets, but instead, only has to have one such body. Manufacturing advantages connected with cost and inventory exist if only one raw part is necessary as compared to a situation in which two raw parts are necessary

Another advantage connected with the bi-directionality concerns the amount of inventory a user must maintain to be able to replace pockets. In this regard, in a situation where there are three basic pockets (i.e., the straight pocket, the cross-over pocket and the offset pocket), the bi-directional capability of the pockets requires that only three pockets be kept in inventory. This is in comparison to keeping six different pockets (left and right hand straight pockets, left and right hand cross-over pocket and left and right hand offset pockets) wherein the pockets do not have a bi-directional capability.

Referring to <figref idrefs="DRAWINGS">FIGS. 19 and 20</figref>, there is shown a specific embodiment of the stump cutter tooth of the invention generally designated as <b>40</b>. Stump cutter tooth <b>40</b> has an elongate cutter tooth body <b>42</b> that has an axial forward end <b>44</b> and an axial rearward end <b>46</b>. The cutter tooth body <b>42</b> has a cylindrical shank <b>48</b> adjacent to the axial rearward end <b>46</b>. The shank <b>48</b> contains a groove <b>50</b>. When the stump cutter tooth <b>40</b> is within the bore of a supporting structure, a clip (not illustrated) engages the groove <b>50</b> to securely retain the stump cutter tooth <b>40</b> to the supporting structure such as, for example, supporting structure. Although the shank contains a groove, it should be appreciated that the axial rear end portion of the shank could be threaded (such as for the embodiment of <figref idrefs="DRAWINGS">FIG. 21</figref>) whereby a nut would be used to secure the stump cutter tooth to the pocket.

The cutter tooth body <b>42</b> has an enlarged head portion <b>56</b> at the axial forward end <b>44</b> thereof. The head portion <b>56</b> has a pair of spaced apart support faces <b>58</b> and <b>60</b> that are separated by a shoulder <b>62</b>. As seen from <figref idrefs="DRAWINGS">FIG. 20</figref>, a generally vertical wall <b>64</b> and a generally horizontal wall <b>66</b> define support face <b>58</b>, and a vertical wall <b>68</b> and a horizontal wall <b>70</b> define support face <b>60</b>. Stump cutter tooth <b>40</b> further includes a pair of hard inserts (<b>72</b>, <b>88</b>) affixed to the head portion <b>56</b>.

Hard insert <b>72</b> has a bottom surface <b>74</b>, a top surface <b>76</b>, an inner surface <b>78</b>, an outer surface <b>80</b> and opposite side surfaces <b>82</b>. The hard insert <b>72</b> also has a primary cutting edge <b>84</b> at the juncture of the top surface <b>76</b> and the outer surface <b>80</b>. The inner surface <b>78</b> is closer to the central longitudinal axis E-E of the cutter tooth body <b>40</b> than is the outer surface <b>80</b>. Hard insert <b>72</b> is affixed to the support <b>58</b> (see <figref idrefs="DRAWINGS">FIG. 20</figref>) by brazing or the like wherein a portion of the inner surface <b>78</b> is adjacent to the vertical wall <b>64</b> and the bottom surface <b>74</b> is adjacent to the horizontal wall <b>66</b>.

Hard insert <b>88</b> has a bottom surface <b>90</b>, a top surface <b>92</b>, an inner surface <b>94</b>, an outer surface <b>96</b> and opposite side surfaces <b>98</b>. The inner surface <b>94</b> is closer to the central longitudinal axis A-A of the cutter tooth body <b>40</b> than is the outer surface <b>96</b>. The hard insert <b>88</b> also has a primary cutting edge <b>100</b> at the juncture of the top surface <b>92</b> and the outer surface <b>96</b>. Hard insert <b>88</b> is affixed to the support face <b>60</b> by brazing or the like wherein a portion of the inner surface <b>94</b> is adjacent to the vertical wall <b>68</b> and the bottom surface <b>90</b> is adjacent to the horizontal wall <b>70</b>.

Prior to operation, the operator must orient the stump cutter tooth <b>40</b> to select which one of the primary cutting edges (<b>84</b>, <b>100</b>) will primarily impinge (or engage) upon the material (e.g., earth strata, wood products and the like) to be impinged and disintegrated, and then fasten the stump cutter tooth <b>40</b> in the selected orientation. During operation, the selected primary cutting edge (<b>84</b>, <b>100</b>) impinges the material and experiences a greater amount of wear as compared to the other cutting edges. Over time, the selected primary cutting edge wears to a point where it does not function in an efficient and/or useful fashion. At this point (or shortly prior to this point), the operator will need to unfasten the stump cutter tooth <b>40</b> and rotate it 180 degrees to orient the other hard insert so its primary cutting edge primarily impinges upon the material. As can be appreciated, stump cutter tooth <b>40</b> provides an indexable cutter tooth that is relatively easy to unfasten and rotate to expose a new primary cutting edge.

<figref idrefs="DRAWINGS">FIG. 21</figref> illustrates another specific embodiment, which is the preferred embodiment, of the stump cutter tooth generally designated as <b>300</b>. Stump cutter tooth <b>300</b> has a central longitudinal axis F-F. Stump cutter tooth <b>300</b> has an elongate cutter tooth body <b>302</b> with an axial forward end <b>304</b> and an axial rearward end <b>306</b>. The cutter tooth body <b>302</b> has a head portion <b>308</b> adjacent to the axial forward end <b>304</b>, and a shank portion <b>310</b> adjacent to the axial rearward end <b>306</b>. The head portion <b>308</b> presents a pair of opposite seating surfaces <b>312</b> and <b>314</b> wherein each seating surface has a generally vertical and a generally horizontal (as viewed in <figref idrefs="DRAWINGS">FIG. 21</figref>) surface. These seating surfaces <b>312</b>, <b>314</b> are disposed about one hundred eighty degrees apart. The shank portion <b>310</b> has a threaded portion <b>320</b>.

The head portion <b>308</b> further defines a flat stop surface <b>316</b> which is intended to abut against the shoulder in any one of the embodiments of the pocket when the stump cutter tooth <b>300</b> is retained by the pocket. The head portion <b>308</b> defines another flat stop surface disposed 180° from the flat stop surface <b>316</b>.

Stump cutter tooth <b>300</b> further includes a pair of hard inserts <b>324</b>A and <b>324</b>B. Each one of the hard inserts (<b>324</b>A, <b>324</b>B) has a generally arcuate flank surface (<b>326</b>A, <b>326</b>B) a generally planar top rake surface (<b>328</b>A, <b>328</b>B) and a generally planar rear surface (<b>330</b>A, <b>330</b>B). It should be appreciated that top rake surface <b>328</b>A of hard insert <b>324</b>A lies in a first plane, and top rake surface <b>328</b>B of hard insert <b>324</b>B lies in a second plane. The first plane is different from the second plane. An imaginary line that is perpendicular to the first plane intersects a second imaginary line that is perpendicular to the second plane at an acute angle.

It should be appreciated that the generally planar rake surface, as well as the rear surface, could present a convex or a concave shape depending upon the specific application. It should be appreciated that the generally planar surfaces presented by the other hard inserts described herein could be convex or concave in shape.

The cutting edges <b>332</b>A and <b>332</b>B are at the intersections of the flank surfaces <b>326</b>A and <b>326</b>B, respectively, and the top surfaces <b>328</b>A and <b>328</b>B, respectively, wherein each one of the cutting edges (<b>332</b>A, <b>332</b>B) has a generally arcuate shape. The hard inserts are spaced apart a small distance, which means that the rear surfaces of the hard inserts are spaced a small distance from one another. During use, either one of the hard inserts (<b>324</b>A, <b>324</b>B) may become chipped or the like. It should be understood that the chipping of one of the hard inserts does not immediately cause chip damage to the other of the hard inserts due to the non-continuous nature of using separate hard inserts (or the physical distinctness or separateness of the hard inserts) instead of using a hard insert with one continuous unobstructed front face. In the alternative, the hard inserts <b>324</b> could be in abutment with one another at the rear surfaces <b>330</b>. However, even if the hard inserts are in abutment, they still remain as separate and physically distinct members so as to possess the above advantage that retards the chipping.

Such as is shown in <figref idrefs="DRAWINGS">FIG. 23</figref> in conjunction with the straight pocket <b>230</b>, it is clear that the reduced portion <b>252</b> of the straight pocket <b>230</b> is narrower (i.e., has a lesser width as viewed from the edge in <figref idrefs="DRAWINGS">FIG. 23</figref>) than the stump cutting tooth at every point directly behind the front face of the stump cutting tooth during the time that the tooth-pocket assembly rotates so that the pocket is protected from excessive wear due to impingement.

Each one of the hard inserts (<b>324</b>A, <b>324</b>B) is made from a hard material such as, for example, cemented (cobalt) tungsten carbide. In this regard, a typical nominal composition of cemented (cobalt) tungsten carbide contains about 9.5 weight percent cobalt with the balance tungsten carbide and recognized impurities. It should also be appreciated that there may be additives (e.g., niobium, tantalum, titanium, chromium) that provide certain properties to the cemented (cobalt) tungsten carbide. The binder (i.e., cobalt) may also include iron and/or nickel. The average grain size of the tungsten carbide (or other hard particles) may be selected to impart desired properties to the cemented (cobalt) tungsten carbide. It is contemplated that the hard insert may also be made from any one of polycrystalline diamond material, ceramics (e.g., alumina-based ceramics) or cermets (titanium-based cermets).

It should be appreciated that the hard inserts exhibit a hardness that is greater than the hardness of the cutter bit body. Thus, it can be appreciated that the axial forward portion of the stump cutter tooth is harder than the axial rearward portion thereof. It is contemplated that in some instances, the axial forward portion of the cutter tooth body may exhibit a higher hardness than the balance of the cutter tooth body.

Brazing is the preferred way to affix the hard inserts to the elongate body. One typical braze alloy is TRICON 080 which has a composition in weight percent of about 54.85% copper, about 25.00% zinc, about 8.00% nickel, about 12.00% manganese and about 0.15% silicon. This braze alloy is available from Tricon, Inc., 2325 Wisconsin Avenue, Downers Grove, Ill. 60515.

It should be appreciated that the hard inserts may also be affixed to the cutter tooth body via an adhesive such as, for example, an epoxy. Further, it is contemplated that the hard inserts may be affixed to the cutter tooth body via mechanical means such as, for example, a clamp or bolt or the like that mechanically acts on the hard insert.

It should be appreciated that the steel bodies for the stump cutter teeth pockets can be made via a number of different processes including a process to quench and temper a carbon steel or an alloy steel. These pockets and cutter tooth bodies could also be cold headed forged or hot forged or investment cast or machined from wrought steel. For the steel body of the stump cutter tooth, a preferred material is a AISI/SAE 15B37 MOD material that has been quenched and tempered to a hardness within the range of about 40 to about 45 Rockwell “C” per a process shown and disclosed in U.S. Pat. No. 4,627,665. For the pockets, a preferred material is a hot forged AISI/SAE 4140H steel that has been quenched and tempered to a hardness within a range of about 35 to about 40 Rockwell “C”.

It should be pointed out that the above discussion of the materials for the hard inserts and the cutter bodies and pockets, as well as the materials for the braze alloys, and other means to attach the hard inserts to the cutter bodies and the hardness profiles of the cutter bodies and the relative hardness of the hard inserts as compared to the cutter bodies apply to all of the specific embodiments of the stump cutter teeth and pockets, even if not specifically set forth in conjunction therewith.

In reference to <figref idrefs="DRAWINGS">FIGS. 21 and 22</figref>, which shows a combination of the stump cutter tooth <b>300</b> and the offset pocket member <b>360</b>, the abutment surfaces <b>316</b> on the stump cutter tooth <b>300</b> are disposed behind the hard inserts of the stump cutter tooth <b>300</b> when the cutting wheel <b>26</b> is rotating in one direction. One abutment surface <b>316</b> is in operative engagement with the first shoulder <b>390</b>A of the offset pocket member <b>360</b> to prevent rotation of the stump cutter tooth <b>300</b> with respect to the offset pocket member <b>360</b>.

The stump cutter tooth <b>300</b> has a second position with respect to the pocket member <b>360</b> wherein the second abutment surface of the stump cutter tooth <b>300</b> is in contact with the second shoulder <b>390</b>B of the offset pocket member <b>360</b> whereby the leading edge of the stump cutter tooth <b>300</b> is reversed and thereby shields the second edge of the pocket member and the second shoulder <b>390</b>B of the pocket member <b>360</b> from wear. It is shown that the hard insert is at least as wide as the radial outer portion of the pocket member <b>360</b> so as to shield the radial outer portion of the offset pocket member from excessive wear. It is also shown that the stump cutter tooth has an unobstructed front face wherein every point on the first or second shoulders follows directly behind, and is thereby shielded by, the front face as the cutting wheel rotates.

During operation using the stump cutter tooth <b>300</b>, one of the hard inserts <b>324</b> engages the material being cut (e.g., a stump) and can be considered to be the engaged hard insert. It is believed that the other hard insert, which is the non-engaged hard insert, functions to provide protection to the pocket in the region adjacent to the non-engaged hard insert. It is believed that the non-engaged hard insert providing this protection, contributes to the increase in the useful life of the stump cutter tooth and pocket. It is contemplated that as an alternative embodiment, the stump cutter tooth may have a first hard insert that functions as a cutting insert (i.e., presents a cutting edge) and a second hard insert or hard region that is oppositely disposed to the first hard insert. The second hard insert may optionally not have a cutting edge and would be expected to provide protection to the pocket in a manner similar to the non-engaged hard cutting insert of cutter tooth <b>300</b>.

Referring to <figref idrefs="DRAWINGS">FIG. 23</figref>, there is shown the relationship between two straight pockets <b>230</b> (with a stump cutter tooth <b>300</b> mounted in each pocket) affixed in the vicinity of the periphery of the driven wheel. As described hereinabove in conjunction with <figref idrefs="DRAWINGS">FIG. 5A</figref> with reference to <figref idrefs="DRAWINGS">FIG. 18</figref>, the cap screws enter through the counterbored bore and pass through corresponding holes in the wheel. The threaded shank of the cap screw engages the threaded bores in the corresponding pocket and the pockets are secured to the wheel through tightening of the cap screws.

Referring to <figref idrefs="DRAWINGS">FIG. 24</figref>, there is shown the relationship between a cross-over pocket and an offset pocket <b>360</b> (with a stump cutter tooth <b>300</b> mounted in each pocket) when they are affixed in the vicinity of the periphery of the driven wheel. As described hereinabove in conjunction with other pocket members, the bolts enter through the counter bored bore and pass through corresponding holes in the wheel. The threaded shank engages the threaded bores in the corresponding pocket and the pockets are secured to the wheel through tightening of the bolts.

Referring to <figref idrefs="DRAWINGS">FIG. 25</figref>, there is shown the relationship between two offset pockets (with a stump cutter tooth mounted in each pocket) affixed in the vicinity of the periphery of the driven wheel. As shown in <figref idrefs="DRAWINGS">FIG. 18</figref>, the cap screws enter through the counterbored bore and pass through corresponding holes in the wheel. The threaded shank engages the threaded bores in the corresponding pocket and the pockets are secured to the wheel through tightening of the cap screws.

Referring to <figref idrefs="DRAWINGS">FIG. 26</figref>, there is shown a side view showing a stump cutter tooth assembly (i.e., stump cutter tooth <b>300</b> and offset pocket <b>360</b>) mounted to the driven cutting wheel in the vicinity of the periphery thereof. There are shown radial arcs that illustrate the clearance between the cutting edge of the stump cutter tooth and the top surface of the pocket. It can be seen that the cutting edge <b>332</b>A of the hard insert <b>324</b>A extends radially outwardly past (so that it is at least as far) the radial outer portion (or radial outer end <b>366</b>) of the pocket member <b>360</b>. As shown by <figref idrefs="DRAWINGS">FIG. 26</figref>, there is a clearance between the arc defined by the cutting edge of the engaged hard insert and the radial outward surface of the pocket.

It is believed that by increasing this clearance, which is the case with the stump cutter tooth as shown in <figref idrefs="DRAWINGS">FIG. 21</figref>, the hard insert <b>324</b>A shields the radial outer portion of the pocket <b>360</b> so that there is an increase in the protection from wear for the radial outward surface of the pocket, as well as the nut that secures the stump cutter tooth to the pocket. In other words, these portions of the pocket do not experience as much impingement from direct contact with the uncut stump and/or the debris resulting from the stump Cutting operation. The useful life of the stump cutter assembly is increased by providing this increase in protection to the pocket. Still referring to <figref idrefs="DRAWINGS">FIG. 26</figref>, it can be seen that first edge also extending radially inwardly in front of the first shoulder for shielding the front shoulder from excessive wear during rotation.

Referring to the specific embodiment illustrated in <figref idrefs="DRAWINGS">FIGS. 27 and 28</figref>, there is shown another embodiment of a stump cutter tooth <b>110</b> that has a cutter tooth body <b>112</b> with an axial forward end <b>114</b> and an axial rearward end <b>116</b>. The cutter tooth body <b>112</b> has a shank <b>118</b> at the rearward end <b>116</b> thereof wherein the shank <b>118</b> has a threaded section <b>120</b>. The cutter tooth body <b>112</b> has a head section <b>122</b> at the axial forward end <b>114</b> thereof. The head section <b>122</b> presents three lobed support surfaces <b>124</b> wherein each one of the support surfaces <b>124</b> is the same.

Stump cutter tooth <b>110</b> further includes a trio of hard inserts <b>134</b> wherein each support surface <b>124</b> carries a hard insert <b>134</b>. Each hard insert <b>134</b> has an arcuate primary cutting edge <b>136</b>

Prior to operation, the operator must orient the stump cutter tooth <b>110</b> to select which one of the three primary cutting edges <b>136</b> will primarily impinge upon the material (e.g., earth strata, wood products and the like) to be impinged and disintegrated, and then fasten the stump cutter tooth <b>110</b> in the selected orientation. During operation, the selected primary cutting edge <b>136</b> impinges the material and experiences a greater amount of wear as compared to the other cutting edges. Over time, the selected primary cutting edge wears to a point where it does not function in an efficient and/or useful fashion. At this point (or shortly prior to this point), the operator will need to unfasten the stump cutter tooth <b>110</b> and rotate it 120 degrees to orient the other hard insert so its primary cutting edge primarily impinges upon the material. As can be appreciated, stump cutter tooth <b>110</b> provides an indexable cutter tooth that is relatively easy to unfasten and rotate to expose a new primary cutting edge.

Referring to the specific embodiment illustrated in <figref idrefs="DRAWINGS">FIGS. 29 and 30</figref>, there is shown still another embodiment of a stump cutter tooth generally designated as <b>150</b> that has a cutter tooth body <b>152</b> with an axial forward end <b>154</b> and an axial rearward end <b>156</b>. The cutter tooth body <b>152</b> has a shank <b>158</b> at the rearward end <b>156</b> thereof wherein the shank <b>158</b> has a threaded section <b>160</b>. The cutter tooth body <b>152</b> has a head section <b>162</b> at the axial forward end <b>154</b> thereof. The head section <b>162</b> presents three lobed support surfaces <b>164</b> wherein each one of the support surfaces <b>164</b> is the same.

Stump cutter tooth <b>150</b> further includes a hard insert <b>170</b> that presents three distinct lobes (<b>172</b>, <b>174</b>, <b>176</b>). Each one of the lobes <b>172</b>, <b>174</b>, <b>176</b> presents a primary arcuate cutting edge <b>178</b>, <b>180</b> and <b>182</b>, respectively.

Prior to operation, the operator must orient the stump cutter tooth <b>190</b> to select which one of the three primary cutting edges (<b>178</b>, <b>180</b>, <b>182</b>) will primarily impinge upon the material (e.g., earth strata, wood products and the like) to be impinged and disintegrated, and then fasten the stump cutter tooth <b>150</b> in the selected orientation. During operation, the selected primary cutting edge (e.g., <b>178</b>) impinges the material and experiences a greater amount of wear as compared to the other cutting edges. Over time, the selected primary cutting edge wears to a point where it does not function in an efficient and/or useful fashion. At this point (or shortly prior to this point), the operator will need to unfasten the stump cutter tooth <b>150</b> and rotate it 120 degrees to orient another cutting edge (e.g., <b>180</b>) to impinge upon the material. As can be appreciated, stump cutter tooth <b>150</b> provides an indexable cutter tooth that is relatively easy to unfasten and rotate to expose a new primary cutting edge.

Referring to the specific embodiment illustrated in <figref idrefs="DRAWINGS">FIGS. 31 and 32</figref>, there is shown yet another embodiment of a stump cutter tooth generally designated as <b>490</b> that has a cutter tooth body <b>492</b> with an axial forward end <b>494</b> and an axial rearward end <b>496</b>. The cutter tooth body <b>492</b> has a shank <b>498</b> at the rearward end <b>496</b> thereof wherein the shank <b>498</b> has a threaded section <b>500</b>. The cutter tooth body <b>492</b> has a head section <b>502</b> at the axial forward end <b>494</b> thereof. The head section <b>502</b> presents four lobed support surfaces (<b>504</b>, <b>506</b>, other lobed sections not illustrated) wherein each one of the support surfaces is the same.

Stump cutter tooth <b>490</b> further includes a hard insert generally designated as <b>508</b> that has a top surface <b>510</b> and a bottom surface <b>512</b>. A peripheral side surface <b>514</b> joins the top surface <b>510</b> and the bottom surface <b>512</b>. The hard insert <b>508</b> presents four distinct lobes (<b>520</b>, <b>522</b>, <b>524</b><b>526</b>). Each one of the lobes (<b>520</b>, <b>522</b>, <b>524</b>, <b>526</b>) has a cutting edge <b>530</b>, <b>532</b>, <b>534</b>, <b>536</b>, respectively.

Prior to operation, the operator must orient the stump cutter tooth <b>490</b> to select which one of the four primary cutting edges (<b>530</b>, <b>532</b>, <b>534</b>, <b>536</b>) will primarily impinge upon the material (e.g., earth strata, wood products and the like) to be impinged and disintegrated, and then fasten the stump cutter tooth <b>490</b> in the selected orientation. During operation, the selected primary cutting edge (e.g., <b>530</b>) impinges the material and experiences a greater amount of wear as compared to the other cutting edges. Over time, the selected primary cutting edge wears to a point where it does not function in an efficient and/or useful fashion. At this point (or shortly prior to this point), the operator will need to unfasten the stump cutter tooth <b>490</b> and rotate it 90 degrees to orient another cutting edge (e.g., <b>532</b>) to impinge upon the material. As can be appreciated, stump cutter tooth <b>490</b> provides an indexable cutter tooth that is relatively easy to unfasten and rotate to expose a new primary cutting edge.

It should be appreciated that enhanced operational efficiency can be achieved when a driven wheel carries a combination of the offset pockets along with the cross-over pockets and the straight pockets. In this regard, the majority of the pockets are the offset pockets. The cross-over pockets and the straight pockets are intermittently positioned between the offset pockets. The presence of the cross-over pockets and the straight pocket allows for the stump cutter teeth carried thereby to function to break up the wider piece of material left between the opposing offset pockets. The combination of the stump cutter teeth carried by the offset pockets and the cutter teeth carried by the cross-over pockets and the straight pockets provides for an enhanced operational efficiency of the stump cutter apparatus.

It should also be appreciated that the abutment between the shoulder on the pocket (straight or offset) and the shoulder or flat surface on the stump cutter tooth facilitate the retention of the stump cutter tooth in a non-rotatable condition. By maintaining the tooth in such a non-rotatable condition, the overall operation of the stump cutter apparatus is enhanced.

It should also be appreciated that the stump cutter tooth <b>300</b> has the feature of being able to be rotated 180 degrees to present a new hard insert. This feature provides for an easier and less time-consuming way to replace a broken or worn hard insert with a new hard insert. By providing an easier and less time-consuming way to replace a broken or worn hard insert with a new hard insert, the present invention enhances the operational efficiency of the stump cutter apparatus.

It is clear that the present invention provides an improved stump cutter tooth that experiences a reduction in events (e.g., the breakage or wear) that require replacement thereof. Further, the present invention provides an improved stump cutter tooth assembly (including the pocket and associated components) that experiences a reduction in events (e.g., the breakage or wear) that require replacement of the other components of the stump cutter tooth assembly including without limitation the pocket and associated fasteners. Among other things, the capability of the stump cutter tooth to provide either a hard region or a non-engaged hard insert that provides protection to the pocket facilitates the reduction in the breakage and/or wear of the stump cutter tooth.

Also, the present invention provides an improved stump cutter tooth, as well as an assembly that uses the improved stump cutter tooth, that enhances the operational efficiencies connected with replacement of stump cutter teeth or other components of the stump cutter assembly. Among other things, the capability of the stump cutter tooth to be indexed 180 degrees so as to present a new cutting edge of a previously non-engaged hard insert increases the serviceability and reduces downtime connected with the operation of the stump cutter. Further, the bi-directional capability of the different styles of pockets increases the serviceability and reduces downtime connected with the operation of the stump cutter.

The patents and other documents identified herein are hereby incorporated by reference herein. Other embodiments of the invention will be apparent to those skilled in the art from a consideration of the specification or a practice of the invention disclosed herein. It is intended that the specification and examples are illustrative only and are not intended to be limiting on the scope of the invention. The true scope and spirit of the invention is indicated by the following claims.